A recent study provided the most comprehensive study of whooping cough bacteria ever conducted.
The researchers hoped to gain insight into the "origin and evolution" of the bacteria, a Wellcome Trust Sanger Institute news release reported.
Whooping cough kills 195,000 children every year globally. A genomic analysis that looked at over 323 strains of the Bordetella pertussis bacteria revealed how vaccines had changed the illness over the years. Vaccines greatly reduced the rate of infection between 1940 and 1960, but many strains have not been completely eradicated.
"The scale of this study and the detailed family history of B. pertussis we are able to draw from it illustrate the journey this bacterium has taken since its emergence," Doctor Simon Harris, a first author at the Wellcome Trust Sanger Institute, said in the news release. "By seeing how an organism escapes vaccination we can build better strategies to control and eradicate it."
Researchers believe the living strains could be thriving in the unvaccinated population, but "highly-vaccinated" populations such as Australia and the United States still have strains of the bacteria. The current switch to acellular vaccines could help build immunity even more.
"To stem the rise of whooping cough without returning to whole-cell vaccines, which can be reactogenic, we need to employ strategic vaccination," Doctor Marieke Bart, a first author from the National Institute of Public Health and the Environment, the Netherlands, said in the news release. "This could include vaccinating mothers in pregnancy so babies are born with some level of protection and cocooning a newborn by vaccinating adults around it. In the long run, however, we need better pertussis vaccines."
Whooping cough popped up about 500 years ago according to the recent analysis; past speculations had suggested the bacteria developed during the Neolithic period over 10,000 years ago.
"Over the past five years or so it has become clear that we have got our dating in bacteriology wrong," Professor Julian Parkhill, a senior group leader at the Sanger Institute and a senior author of the study, said in the news release."The mutation rate we were working with is probably two orders of magnitude out, so we thought the last common ancestor of these modern B. pertussisstrains was tens of thousands of years old when, in fact, it is much younger than that."
